Grain-cleaning machine



July 13 1926. 1,592,752

c. BENTHAM GRAIN CLEANING maxim:

Filed August 51. 1925 Patented July 13, 1926.

it UNITED STATES PATENT OFFICE.

CECIL BENTHAM, F MANCHESTER, ENGLAND, ASSIGNOR TO HENRY SIMON LIMITED,OF MANCHESTER, ENGLAND, A 'BRITISI-I COMPANY.

GRAIN-CLEANING MACHINE.

Application filed August 31, 1925, Serial No. 53,694, and in GreatBritain January 24, 1925.

drawn, the said fan dividing the dust laden air into two portions, oneportion, which 1s the main portion, being slightly laden with dust andthe other portion which is heavily laden with dust being passed.

through a dust separator and collector, and

the whole of the air being then re-circulated through the grain. lVithsuch an arrangement, self-sealing rotary valves have to be provided forcontrolling the delivery of dust from the separator and collector.

The object of my present invention is to simplify the construction andarrangement of grain cleaning machine of the type before referred to, toobviate the employment of rotary self-sealing type valves on the dustseparator with freedom from the emis sion of dust laden air from themachine, and to obtain a highly eflicient cleaning action.

My invent-ion comprises a grain cleaning machine of the type referredto, in which the air from the dust separator and collector is returnedto the air circulation circuit at a point between the place where themain air first acts upon the grain and the suction inlet of the doublefan.

My invention further comprises the combination with an aspirating deviceby which the dust, chaff, and other impurities are separated from thegrain, and a double fan dividing the air into two portions, one portionbeing slightly and the other heavily laden with dust, the latter portionbeing passed through a dust separator and collector, of means causingthe grain to be cleaned to pass twice through the air delivered dirootfrom the double fan and at a point intermediate between the said twopassages to pass also through the air leaving said dust separator andcollector, the whole of the air being continuously circulated throughthe cleaning machine to and from the double fan.

Referring to the accompanying sheet of explanatory drawings I Figure 1is a diagrammatic sectional elevatioirancl Figure 2 a plan view of oneconvenient arrangement of plant in accordance with my invention.

Figure 3 is a diagrammatic illustration of a modified arrangement ofplant.

The same reference letters in the three views indicate the same orsimilar parts.

In the illustrated applications of my invention, I employ a double typefan a which in known manner serves to divide the air received by it intotwo portions, one slightly and one heavily laden with dust, the latterportion being delivered into a dust separator and collector b. Theformer portion is delivered by the pipe 0 into a conduit (Z down whichthe grain is descending, so as to exerta cleaning action on the grain. Avalve 0 (Figure 2) may be arranged between the double fan and the dustseparator b and a similar valve 7' be provided on the air conduit 0.

The aforesaid known action of the double fan a is clearly shown atFigure 3. The dust laden air entering from the conduit 7' (hereinafterreferred to) enters the fan casing at its left hand side. The heavilydust laden air owing to its superior specific gravity, is driven by thecentrifugal force into the said separator 6 Whilst the air but slightlyladen with dust passes, as shown by the arrows, over the periphery ofthe usual partition disc forming part of the left hand fan and thence tothe right hand fan and into the said pipe 0. v

The grain is delivered into the machine at g from one side of theaspirating conduit cl up which the cleaning air passes, travels acrosssuch conduit or chamber and over a weir plate or the like it into aconduit or branch 2' into which the air from the dust separator may bedelivered as hereinafter described. It then re-enters the aspiratingconduit at a lower point as shown, where it is again subjected to theaction of the air delivered from 0 by the double fan device and leavesthe machine at 19.

The light grain which is carried up the conduit j by the ascending airpasses over into a side channel or deposit chamber is, and travels downa chute-to a collecting hopper or its equivalent.

The dust separator and collector I) may be of any suitable form. Thecontrol valves 5 and f may be utilized to regulate the air currents fromthe double fan and to assist in producing the required air pressure. Thedust outlet of the dust collector is most conveniently arranged to be atan air pressure closely approximating to atmospheric, but the sidechannel or deposit chamber is in which the light grains are collectedmay be at a lower air pressure.

The air from the separator Z) passes by way of the conduit m into thevertical conduit g from which it can be directed by the valve 0 who] yinto the side channel or de posit chamber is to assist in cleaning thelight grain or separating dust therefrom. or wholly into the channel 71to assist in cleaning the main body of grain. Alternatively, the saidair may be directed partly into is and partly into 2'.

By arranging that the delivery of the air from the dust separator 7)takes place after.

the main air "from c has acted upon the grain, I am enabled to obtain alow air pressure within the dustseparator and so dispense withself-sealing valves on the dust delivery connection thereof which canleat to a plain bag serving for dust collecting purposes. 7

In the Figure 1 arrangement, the dust laden air passes through a secondseparator n before entering the fan a. in n will be at or belowatmospheric pressure so thata plain outlet can serve for dust re movalpurposes thereon.

It will be understood that. it desired -the air (which is small involume) from the dust separator b or a part or such air may be takendirectly into the suction inlet of the double tan a without passingthrough the grain.

I claim 1. In grain cleaning machines, the combination wth an aircirculating circuit including a double :tan whereby the air after Thepressure being drawn through the grain passing through the machine isdivided into two portions, said portions being respectively heavily andlightly laden with the grain dust and impurities, including also a dustsepa rator and collector through which the heavily laden air isbye-passed, or means whereby the air leaving the said separator andcollector is returned to the said alr circulating circuit at a positionbetween the place of admission of the grain to the machine and thesuction inlet of said fan.

2. In grain cleaning machines as claimed in claim 1, means whereby thegrain is caused to pass twice through the air delivered directly fromthe said fan and at a point between the said two passages to pass alsothrough air delivered by way of the said separator and collector.

In grain cleaning machines as claimed in claim 1, means whereby air fromthe said separator and collector is utilized to exert a supplementarycleaning effect on the light grain separated from the heavier grain bythe action of the circulating air in said circuit.

4. In grain cleaning machines as claimed in claim 1, means whereby theair from the said separator and collector is divided into two portions,of which one is formed through the light grain separated from theheavier grain by the action of the circulating air in said circuit.

5. In grain cleaning machines as claimed in claim 1, means for theseparation and collection of dust and impurities from the circulatingair after the said air has passed through the grain and. prior to itsentering the said fan. i

In testimony whereof I have signed my name to this specificatioi'i. I

CECIL BENTHARL

